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The Effect of Elliptical Form of Cylinder on Free Convection in Annular Space Elhadi Zoubai1,a* and Bachir Bouhamida1,b Laboratory of LSCMI, Faculty of Mechanical Engineering, USTO-MB, BP 1505, El-Menaouer, Oran, 31000, Algeria ahadi_usto@yahoo.fr, bbouhamida68b@yahoo.fr Keywords: Free convection, thermal science, Newtonian fluid, steady simulation, CFD Abstract.
The space between cylinders is considered to be filled with fluid of different values of thermo-physical properties (Pr).
It was understood that the number of cylinder, the form of cylinder and the kind of the fluid are principal factors that can improve or reduce the heat transfer.
Fig. 2 Mesh for present domain The number of grid elements greatly affects the calculations results, so choosing this number is very important in numerical work.
Through the results, we were able to extrapolate the following points: · The elliptical shape the cylinder effectively affects on heat transfer; · The heat transfer decreases as the aspect ratio increases; · For all considered values of aspect ratio (E), increase in the force of thermal buoyancy (Ra) increases the thermal transfer rate; · The effect of Pr number on the studied geometries is very small

The purpose of this addition is to ascertain how the addition of steel slag will affect the compressive strength of fly ash concrete.
However, it was shown that between 30 and 60% of the coarse aggregate should be replaced with steel slag for the best mechanical qualities (compressive strength, tensile strength, and flexural strength) compared to traditional concrete.
This condition can be caused by several factors, namely the fact that the dimensions of the test object are not precise, the mixture is uneven, and porosity occurs.[14] whereas for presentations, 80% and 100% have a decrease from normal concrete due to an unfavorable crushing mode and have such a large slam value compared to other concrete.
This greatly affects the quality of the concrete because the inaccurate surface on the concrete sample causes uneven loading when the concrete compressive strength test is carried out.
Xiang, “Numerical Simulation of Basic Properties of Full-Steel Slag Aggregate Concrete,” Adv.

In other words, flow behavior is heavily affected by the intensity and orientation of the applied magnetic field.
Ravi Chandra Babu et al. (29) have investigated the MHD chemically reacting and radiating nanofluid over a vertical cone embedded in a porous medium with variable properties.
Under Boussinesq approximation, the governing boundary layer equations in terms of similarity variable can be expressed as (ref (31)) Fig.1: Physical interpretation of the problem (1) (2) (3) (4) Where and The corresponding boundary conditions are (5) Table: 1 Thermophysical properties of water and Cu nanoparticles.
Al-Lawatia, Heat transfer in micro polar fluid along an inclined permeable plate with variable fluid properties, Int.
Jayalakshmi, MHD chemically reacting and radiating nanofluid over a vertical cone embedded in a porous medium with variable properties.

Introduction Compression ignition (CI) engines are excellent choices for agricultural machinery and transportation equipment in account of their high thermal efficiency and mechanical strength in applicants industry.
In addition to having comparable heat capacity, higher cetane number, and oxygen content, biodiesel improves the ignition properties as well as reduces emissions like the PM, carbon monoxide (CO), and carbon dioxide (CO2).
Table 2 Physical and chemical properties of Diesel and spirulina biodiesel blends.
This affects the distribution of local fuel equivalents in the engine cylinder.
This results in less heat being released during the premix combustion stage, as well as a lower combustion temperature as a result of these factors.

A Study on Coldflame Propagation Characteristics Applying Amplified Ignition Source to Overcome Landfill Gas’s Flame Retardant Limit Kyungjin Ryu1,a and Munseok Choe2,b* 1Department of Smart E-Automobile, Yeungnam University College, Daegu 42415, Korea 2Department of Mechanical Vehicles, Chungbuk Provincial University, Okchen, Chungbuk 29046, Korea aangelus999@ync.ac.kr , bcms0290@cpu.ac.kr Keywords: Land fill gas, Amplified ignition source, Coldflame, Spark ignition engine, Flame retardance Abstract.
As the flame propagation occurs, it forms a flame surface and affects the surrounding mixed gas, generating additional energy such as combustion pressure and light.
In order not to affect the experimental results, the external temperature and the temperature of the injected gas were all set identically, and the compression pressure was kept at 3 bar in the experiment.
Figure 3 Schematic diagram of CVCC Table 1 Experimental conditions in the CVCC Properties Specifications Compressed pressure 3bar Initial temperature Air : 300K, CH4 : 300K, CO2 : 300K Well temperature 350K A/F Ratio 0.8~1.8(from 0.1 unit) Plug type Conventional type plug(C-type), AIS plug(AIS) Conventional energy 0.4J AIS energy 2.03J Table 2 Gas proportion according to each LFG Fuel name Gas proportion (CH4:CO2) LFG70 7 : 3 LFG60 6 : 4 LFG50 5 : 5 LFG40 4 : 6 Results and Discussion 3.1.
Scheutz, Measuring methane emissions from a UK landfill using the tracer dispersion method and the influence of operational and environmental factors, Waste Management, 87 (2019) pp. 870-882

Deleterious effect on material integrity and mechanical properties resulting from failure caused by corrosion process is severe in some cases.
The corrosion of a metal or a material is a global scientific problem as it affects different walks of life especially in metallurgical, chemical, materials and oil industries.
Corrosion is defined as the degradation of materials or its properties due to a reaction with the environment.
The adsorption process is affected by the chemical structures, allocation of charge in molecule, the nature and apparent charge of metal, and the type of aggressive media [25].
[34] Fuchs Godec, R., and Zerjav, G., (2009), Inhibition properties of Triton – X – 100 on Ferritic Stainless steel in Sulphuric Acid at Increasing Temperature, Acta chimica Slovenica, 56(1): 78 – 85

Metal selenide semiconductor nanocrystals, or nanoparticles are receiving remarkable research attention because of their size-dependent optical and electrical properties [18].
Among the many metal selenide known, gallium selenide which is a member of III–VI group has a number of interesting properties for electrical and nonlinear optical applications [19,20].
Usually, the nature of the interaction between the conduction and valence bands as well as the size of the band gap determines the optical properties of semiconducting nanocrystals.
The Atomic Force Microscope (AFM) is a tool currently being used to solve processing and material problems in a wide range of technologies affecting the electronics, telecommunications, biological, chemical, automotive, aerospace, and energy industries.
Pizani, GaSe formation by mechanical alloying Ga50Se50 mixture.

Within the DSA temperature a sharp decline in the fracture properties was observed.
The present investigation that characterizes the tensile and fracture properties of two alloy variants of the steel would provide valuable information for design of microstructure specifically catering to resistance to brittle fracture and also to generate a database of material properties which would be an input to fail safe analysis.
The ductility properties passed through a minimum in the temperature range where serrated flow was observed.
On increasing the pull rates by a factor of 10, such perturbations in the load and DCPD signal was not observed.
As a result, the embrittling manifestations of DSA on the mechanical properties of AISI 403 steel are significantly increased.

The objective is to identify optimum configuration in terms of loading, structural dimensions, material properties and composite layup associated with micrometeorites impacts on spacecraft that will not penetrate into its structure.
The impact velocity of a projectile will affect the performance of compliant and resilient laminates.
Through such analysis and numerical simulation, effort is devoted to arrive at the optimum configuration in terms of loading, structural dimensions, material properties and composite lay-up, among others.
The problem can be idealized as the loading and response characteristics of a set of bonded rectangular isotropic and homogeneous plates with different material properties, subjected under the impact of a solid and rigid spherical impactor, as depicted in Fig. 1.
(b) To appreciate the use of bi-metallic composite, Fig. 7 exhibits the response of an Aluminum/ Titanium composite with properties tabulated in Table 2 as an isotropic material.

Following conditions were met while carrying out the research: – in terms of their physical properties, natural materials meet the natural conditions; – geometrical parameters of the gasification site are reproduced in the model with the provided principles of static similarity; – lithological structure of the rock coal thickness considers its changes within the deposit area; – hierarchical dependence of the mining and geological factors forming the stress train state of rock mass; – CRMG versatility is provided by the balanced behavior of chemical reactions and physical velocities of the gasification processes.
As for the temperature mode, a chemical reaction is much more sensitive to the temperature changes than to other physical factors.
The Change of Structural and Thermal Properties of Rocks Exposed to High Temperatures in the Vicinity of Designed Geo-Reactor.
IEEE 8th International Conference Nanomaterials: Application & Properties (NAP), 8915065 https://doi.org/10.1109/nap.2018.8915065 [34] Koveria, A., Kieush, L., Hrubyak, A., & Kotsyubynsky, V. (2019).
Properties of Donetsk basin hard coals and the products of their heat treatment revealed via Mossbauer spectroscopy, Petroleum and Coal, 61(1), 160-168 [35] Kieush, L. (2019).